Mammography prevents morbidity and mortality by detecting breast cancer at an early stage. However, the optimal screening interval is intensely debated. The American Cancer Society1 and other groups2- 4 have recommended annual screening for women 40 years and older. In contrast, the US Preventive Services Task Force (USPSTF) recommends biennial screening for women aged 50 to 74 years.5,6 Annual screening has more false-positive test results, resulting in more frequent biopsies, which is one of the reasons the USPSTF recommends less frequent screening. The USPSTF also recommends starting breast cancer screening at age 50 years. The average age at onset of menopause among US women is 51 years, and breast density decreases after menopause. Breast tissue is denser in younger women, increasing the likelihood of false-negative findings because it is more difficult for radiologists to identify small lesions in dense breasts, yet breast density is an independent risk factor for development of breast cancer. Younger women also have more false-positive results. The optimal breast cancer screening strategy is not known because of these contradictions.
Yi M, Hunt KK. Optimizing Mammography Screening Intervals. JAMA. 2015;314(15):1635-1636. doi:10.1001/jama.2015.13149